A number of devices currently exist for fixedly securing a first machine part, such as a sleeve of an inner race ring of a ball bearing, to a second machine part such as a shaft. For example, the first machine part may be directly mounted on the shaft by means of a press fit, shrinkage fit or a glue joint. It is also known in the art to provide the inner race ring of the ball bearing with a clamping sleeve having tapering grooves or threads. The sleeve is fixedly secured to the shaft by a fastener such as a nut. However, the force created by clamping the sleeve against the shaft is generally an axial force. This axial force acts primarily against the inner race ring of the ball bearing and is effected by means of a nut member which is tightened along a threaded portion of the clamping sleeve against an end surface of the first machine part. The clamping sleeve and nut are generally manufactured as separate and distinct elements, thereby resulting in relatively high manufacturing costs and a need for precise mounting.
It is an object of the present invention to provide a clamping device of the type aforementioned requiring less expensive manufacturing methods and allowing for simplified mounting. To this end, the present invention incorporates a ball bearing comprised of an inner ring having an arcuate raceway for a plurality of balls. The inner ring is provided with outwardly projecting sleeve portions which are integral with the ring. The sleeve portions are externally threaded so as to be cooperatively engageable with the internal threads of a locking member such as a nut. The locking member circumscribes the sleeve portion which, in turn, is fitted around a shaft. Upon axial rotation of the locking member about the sleeve portion, the sleeve portion is radially deformed to frictionally lock against the shaft. However, the increase in clamping force occurs mainly under the locking member and not under the raceway of the inner ring. Thus, the raceway of the inner ring maintains its shape. In this way, the ball bearing may be fixedly secured to the shaft.